Apparatus for controlling the count of a sliver fed from a carding machine

ABSTRACT

The invention comprises apparatus for controlling the count of a sliver whilst being fed from a carding machine to ensure a substantially uniform sliver, the sectional size of the sliver being related to a valve setting and passed through sensing means so that any slight variation in the sliver size is sensed and magnified to operate the valve which operates a fluid motor which in turn operates variator control means capable of causing correction of the sliver size.

1;; 19 [111 3,827,106 Varga Aug. 6, 1974 [54] APPARATUS FOR CONTROLLING THE 3,644,964 2/1972 Varga 19/240 COUNT OF A SLIVER FED FROM A CARDWG MACHINE Inventor: John Maximilian Jules Varga,

Halifax, England Assignee: Carding Specialists (Canada) Limited, Toronto, Canada Filed: Nov. 29, 1971 Appl. N0.: 202,927

Related US. Application Data Division of Ser. No. 854,170, Aug. 29, 1969, Pat. No. 3,644,964.

Foreign Application Priority Data Sept..3, 1968 Great Britain 41750/68 US. Cl. 19/240 Int. Cl D0lh 5/38 Field of Search 19/239, 240, 241; 137/568,

References Cited UNITED STATES PATENTS 12/1963 Selby 19/240 FOREIGN PATENTS OR APPLICATIONS 650,713 9/1937 Germany 137/625.69 930,873 7/1963 Great Britain.. 19/240 612,891 11/1960 Italy 19/240 Primary ExaminerDorsey Newton Attorney, Agent, or Firm-Stevens, Davis, Miller & Mosher ABSTRACT and passed through sensing means so that any slight variation in the sliver size is sensed and magnified to operate the valve which operates a fluid motor which in turn operates variator control means capable of causing correction of the sliver size.

4 Claims, 11 Drawing Figures PATENTEI] AUG 6 I974 SHEET 2 [1F 9 PATENTEDAUB 6 14 38 27. 106

SHEET 3 (IF 9 s'.'s27;10e

PATENTED MIG 6 74 SHEEI t [If 9 PATENTED AUG 61974 SHEET 6 BF 9 This application is a division of copending application, Ser. No. 854,170, filed Aug. 29, 1969, now U.S. Pat. No. 3,644,964.

This invention relates to the formation of slivers in carding machines.

It is often difficult to maintain a high degree of uniformity in slivers during processing and various methods and means have been tried to solve this problem. The main object during the formation of slivers is to try and keep a constant count, i.e., weight per unit length, and it is theobject of this invention to provide an improved arrangement for this purpose.

The optimum type of feed back for the automatic correction of sliver regularity when using so-called closed loop or integrating control systems is of a graduated type where the correction is at all times dependent on the degree and sense of the error signalled. Closed loop auto-levellers in the past have tended to have complex electronic control systems in order to provide smooth correction, or have compromised with one-off controls with a band around the neutral position where no correction is generated.

According to this invention a method of controlling the count of slivers fed from a carding machine consists in relating the sectional size of a sliver to a normal setting of valve control means, sensing said given sliver sectional size in relation to said setting during linear movement of the sliver, causing any variation in such sliver size from normal to move the valve from its set position and thus control the direction and rate of flow of fluid to a fluid motor to cause said motor to control variator control means capable of causing correction of the sliver size, and arranging any particular position of the variator control means to correspond with a given speed ratio but not correspond to a given position of the sensing means.

The invention includes apparatus comprising sensing means having sliver engaging surfaces, at least one of said surfaces being movable relative to the other to sense variation in sliver thickness from a given thickness related to a normal setting of valve control means, lever means operable by movement of said one of said surfaces to provide a magnified movement, said valve control means being responsive to said magnified movement to control the direction and rate of flow of fluid to a fluid motor, said motor being adapted to operate variator control means capable of causing correction of the sliver size, any particular position of the variator control means being arranged to correspond with a given speed ratio but not to correspond to a given position of the sensing means.

The fluid pressure control system according to this invention ensures a fully continuous control in a very simple manner. Moreover, the shape of the control curve can be tailored to any form by known modification of the lands of the control valve.

In order to make easier the construction and shaping of such a valve, it is important to give it the maximum degree of movement for a given movement of the sensing means which is very small in general. By coupling the valve to the end of a reasonably linearly magnifying leverage system, it is possible to construct a very simple, reliable and rugged valve, not sensitive to dirt and contamination and enabling it to be put on to ball bearings.

A particular embodiment of the invention will now i be described in more detail, by way of example, with reference to the accompanying drawings in which:

FIG. 1 is a schematic view of the general assembly of the complete apparatus,

FIGS. 2A and 2B show a part side elevation part section of part of the control apparatus;

FIG. 3 is a section on line III-III of FIGS. 2A and 28,

FIG. 3A is a section on line 3A of FIG. 3;

FIGS. 4A and 4B show a section on line IVIV of FIGS. 2A and 28;

FIGS. 5A and 5B show a cross section on line VV of FIGS. 2A and 2B;

FIG. 6 is an end elevation partly in section of a further part of the assembly; and

FIG. 7 is a side elevation of the part shown in FIG. 6.

Referring now to FIG. 1 this shows a carding machine 1 fed with a web of cotton 2 by a lap feed 3. Carded cotton leaving the machine enters a condensing trumpet 4 and from there passes between two rollers, an upper roller 5 and a lower roller 6. The upper and lower rollers are driven from the drive to the carding machine. The upper roller 5 is rotatably carried by one member of a lever system indicated generally at 7, so that the upper roller can move relative to the lower roller. These movements take place in response to variations in thickness of a sliver passing between the rollers and this movement is magnified by the lever system 7 to give a magnified movement at an end 8 of a lever forming part of the system. The end 8 is connected to a spool 9 of a spool valve 10 and the spool controls flow of low pressure fluid from a pump 11 driven from the carding machine drive 11a. The spool 9 has two lands controlling outlet ports 12 and 13 from the housing 10, and the outlet ports 12 and 13 are connected to pass fluid to opposite sides'of a piston 14 working in a cylinder 115. The piston 14 has a piston rod 16 which is connected to means for shifting a belt 17 of a cone belt drive. The drive comprises a driving roller 18 coupled to the drive to the carding machine and a driven roller 19 coupled to control the speed of the lap feed roll 3.

In operation of the system when the sliver passing between the rollers 5 and 6 is of a desired thickness the spool 9 is in a neutral position wherein the lands close the outlet ports 12 and 13 so that the piston 14 takes up its neutral position and the belt 17 is positioned on the cones so that the lap feed roll is driven at a desired speed. If a variation in sliver thickness occurs then the upper roller 5 is moved from its normal position and so moves the lever system. The magnified movement at the end 8 of the lever system shifts the spool 9 to uncover the outlet port 12 or 13 and allow pressure fluid to pass to one side of the piston 14. The piston thus moves so shifting the belt 17 to vary the transmission ratio between the cones 18 and 19 and thus to change the speed of the lap feed roll 3. The change of speed is effected in a sense such that it will tend to cause'the sliver to return to the desired thickness, and once the sliver has resumed this thickness the system reverts to its neutral condition. The remaining figures show the apparatus in more detail.

Referring to FIGS. 2A and 4A the rollers 5 and 6 between which the slivers pass are of conventional male and female configuration, the roller 6 being formed with a groove in which a rib 21 of the roller 5 fits. The roller 6 is made up of two parts 22 and 23 bolted together by bolts 24 on either side of a spacing member 25 having a width equal to the desired width of the groove 20. From the rollers 5 and 6 the sliver passes to a standard knock-off motion indicated generally at 26. This is of well known construction and need not be described in detail save to mention that it acts to stop the carding machine if the sliver breaks.

A drive shaft 27 is coupled to the drive for the carding machine and is journalled in bearings 28 and 29 secured to a lower housing 30. A gear 31 is splined at 32 to the shaft 27 and meshes with a further gear 33 splined at 34 to a shaft 35 running in bearings 36 and 37 mounted in an upper housing 38. The gear 33 meshes with a gear 39 splined at 40 on one end of a further shaft 41 extending parallel to shaft 35. The shaft 41 is mounted to rotate in bearings 42 and 43 supported in one arm 44 of a bell-crank lever 45. The other end of shaft 41 has the roller 5 splined thereto at 46. The end of shaft 35 remote from the gear 33 is splined at 47 to the lower roller 6. The gearing is such that the rollers 5 and 6 are both driven at the same speed.

A flexible diaphragm 48a is secured by a clip 49a to the arm 44 of the bell-crank lever 45, and is secured by a cover plate 50a to the upper housing 38. The diaphragm 48a allows relative movement of the bell-crank 45 in the upper housing 38 yet prevents dust and moisture from entering the upper housing 38.

Referring now to FIGS. 2A and 5A the bell-crank lever 45 is secured to the outer races 46 and 47 of two bearings 48 and 49 the inner races 50 and 51 of which are secured to a shaft 52. The shaft 52 has a stub 53 which is eccentric to the axis of the shaft, and the stub 53 is rotatably mounted in the upper housing 38. At the end of the shaft 52 remote from the stub 53 there is secured by bolts 54 a knurled adjustment member 55 which is coaxial with the stub 53 and thus lies eccentric to the shaft 52. The knurled member 55 is located against a distance piece 56 secured to the upper housing 38 by bolts 57 and forming a locating member for locating shoulders 58 on the shaft 52. It will be seen that rotation of the knurled member 55 causes the pivotal axis of the bell-crank 45, Le, the axis of the shaft 52 to be moved relative to the housing, and thus allows the distance between the axes of the rollers 5 and 6 with the bell-crank lever in a given angular position to be adjusted.

As shown best in FIG. 3 the bell-crank lever 45 has a lower arm 59 terminating in bifurcated sections 60 and 61. The bifurcated arm 60 surrounds a shaft 62 which is rotatably mounted relative to the arm 60 by a combined bearing and sprag clutch 63. As shown in FIG. 3A, combined bearing and sprag clutch 63 comprises bearings 63A positioned between surface 63B of shaft 62 and outer race 63C. The shaft 62 is supported for rotation relative to the arm 61 by a conventional ball bearing 64, and the shaft 62 carries at one end a gear 65. The shaft is located relative to the various parts by grooves and circlips 66.

Located between the bifurcated arms 60 and 61 of the lower arm 59 of the bell-crank lever is the upper end of a magnifying lever 67. The lever 67 also surrounds the shaft 62 and relative rotation between the lever and the shaft is again allowed by a combined bearing and sprag clutch 68. The lever 67 is pivotally mounted by a bearing 69 about a shaft 70 havng a larger diameter section 71 and a smaller diameter section 72 between which is formed a shoulder 73 against which the bearing 69 is located. The larger diameter section 71 carries a stub 72 which is journalled by way of a bearing 73a in one arm 74 of a bifurcated control lever 76a. The smaller diameter end 72 of the shaft 70 is secured to the inner race of a bearing 75, the outer race of which is fixed to the other arm 74a of the control lever 76c. A distance piece 77 separates the bearing from the bearing 69. The end of shaft 70 remote from the end 72 has secured thereto a gear 78 which meshes with gear 65 carried by the shaft 62.

The pivoting of the bell-crank lever 45 in the housing by the bearings 48 and 49, the pivotal connection between bell-crank lever 45 and magnifying lever 67 by way of the combined bearing and sprag clutches 63 and 68, bearing 64 and shaft 62, and the pivoting of magnifying lever 67 to the lever 760 by hearing 69 round shaft 70 together with the freedom of lever 76c to pivot around the axis of bearings 80, 81, combine to provide a lever system which is virtually friction free. All contacts between the various relatively movable members are rolling contacts rather than sliding contacts. Bearings which are subjected to very small movements at reasonable loads may have a tendency for the balls to slide rather than roll and thus to break down the lubricating film between the balls and the races, an effect known as false brinelling." This effect is substantially reduced in the lever system disclosed by the presence of the combined bearing and sprag clutches 63 and 68. These act so that any small movement of the levers acts to rotate the shaft 62 in one sense only and this positive rotation of shaft 62 ensures rolling contact between the balls and the races and thus prevents or reduces false brinelling. The connection from shaft 62 by way of gears 65 and 78 to shaft 70 ensures that shaft 70 is rotated with shaft 62 and reduces or prevents false brinelling in bearing 69 and in the bearing 75 between shaft 70 and control lever 76c.

The control lever 76c acts to control the position of shaft 70 relative to the housing. The bifurcated arms of the lever 760 are secured to a cage 79 in which are secured the outer races of two bearings 80 and 81, the bearings being retained by circlips 82 and 83. The inner races of the bearings surround a shaft 84 having eccentric ends 85 and 86 supported by bearings 87 and 88 respectively in a cage 89. The cage comprises an upper section 90 bolted by bolts 91 to the upper casing 38, and a lower section 92 bolted by bolts 93 to the upper section 90. The eccentric end 85 of shaft 84 is pinned to an arm 94 having an upper part to which is secured by a pin 95 one end of a tension spring 96, the other end of which is secured by a pin 97 to the upper housing 98. The lower part of arm 94 has a surface 95a bearing against an adjusting member 96a. The adjusting member 960 extends through a bore in a guide sleeve 97a secured by bolts 98 to the lower housing 30. The bore has a threaded section 99 with which a threaded section 100 on adjusting rod 96a engages, and the end of the adjusting rod 96a carries a knurled adjusting member 101. The eccentric end 86 of the shaft 84 is driven by a pin 102 secured to a member 103 rotatably mounted in a bore in a sleeve 104 secured by bolts 105 to the lower housing 30. The end of the member 103 has secured thereto a handle 106.

It will be seen that rotation of the knurled member 101 will cause the adjusting rod 96a to move in the sleeve 97a to control the angular position of the arm 94 and thus of the shaft 84. Rotation of the shaft 84 about the bearings surround the eccentric ends 85 and 86 changes the height of the shaft 84 and thus of the control arm 76. This motion is in turn transmitted back to the bell-crank lever and acts to give a fine adjustment of the distance between the axes of the rollers 5 and 6. Rotation of the handle 106 through 180 from the posi tion shown gives an overriding quick release to the shaft 84 to move this substantially so that the lever system is moved to such an extent that the rib 21 on roller 5 lifts out of the groove on roller 6 to allow any blockage of the sliver in the groove to be cleared. Return of the quick release handle 106 to its original position restores the lever system at its original adjustment. The tension spring 96 acts on the lever 94 to ensure it always returns to its rest position with a constant force thus ensuring the maintenance, with great accuracy, the set angular position of the eccentric shaft 84.

As best shown in FIG. 2B the magnifying lever 67 extends downwardly and terminates at its lower end in a member 107 to which a roller 108 is rotatably secured. The lower end of this lever 67 lies adjacent to a valve shown generally as 109 for controlling a flow of hydraulic fluid. The valve 109 comprises a housing 110 in which a spool 111 is axially slidable. The spool is supported within the housing by ball or roller bearing systems 112 and 113. The bearing system maybe either a recirculating system or a planetary system. In the recirculating system a sleeve member is positioned radially between the spool and the housing, and balls are positioned between the spool and the sleeve member and between the sleeve member and the housing so as to be guided for circulation axially along both surfaces of the sleeve member and around the ends of the sleeve member to pass from one to the other surface thereof. In a planetary system the balls are axially retained in a cage which is positioned radially between the spool and the housing, and are in contact with both the spool and the housing. The spool 111, bearing system 112 and 113, and housing 110 are assembled as a unit and fitted within a bore 114 formed in a block 115 (which may or may not be part of the lower housing 30a) drilled with conduits for hydraulic fluid. The valve assembly is secured in position within the bore 114 by an end plate 116 and bolts 117, such plate acting against the spring 116a which pushes the housing 110 against the circlip l16b. One end of the spool 111 has secured thereto at 118 one end of a tension spring 119 anchored at the other end to a pin 120 secured to the lower housing 30. The spring 119 acts to bias the spool into engagement with the roller 108 at the lower end of the magnifying lever 67. It will thus be seen that movements of the magnifying lever 67 will result in corresponding movements of the spool 111. Moreover the spring 119 also serves to bias the bell-crank lever 45 so that the upper roller 5 is pressed into engagement with a sliver so as to respond to every small variation in thickness of the sliver. Such spring action may be augmented or replaced by a tension spring 119a, although a compression spring may be used. If the spring 119 is dispensed with then the roller 108 and the end 118 of the piston 111 may be held together by a magnetic force.

The housing is formed'with a fluid inlet port 121, two fluid outlet ports 122 and 123 and two fluid drain ports 124 and 125, all of which communicate with appropriate ducts drilled in the block 115. The spool 111 is formed with two lands 126 and 127, which, when the spool is in the neutral position shown in FIG. 2B cover the outlet ports 122 and 123 respectively. The lands 126 and 127 are placed and tapered in a manner to regulate fluid flow and direction dependent on the degree and sense of the displacement. They are designed so that they do not contact the surface of the housing 110 in any position of the spool. Thus, the only contact between the spool and the housing is by way of the ball systems 112 and 113 and all contact is rolling contact rather than sliding contact so rendering the valve essentially friction-free.

Preferably, the hydraulic system controlled by this valve operates at low pressure and this low pressure means that fluid leakage past the lands 126 and 127 is small. What leakage there is either passes equally through outlet ports 122 and 123 or completely around the lands 126 and 127 to pass to drain through drain ports 124 and 125.

Fluid is pumped to the inlet port 121 by a pump indicated generally at 128 and shown in FIGS. 2A, 2B, 4A and 4B. The pump is a self-porting two-stroke pump having pistons 129 and 131) working in cylinders 131 and 132 respectively, fluid flow to each cylinder being controlled by a valve element 133 or 134 carried on the piston 129 or working in the other cylinder. The valve annuli 132a connect with their correct cylinders respectively by appropriate channels in covers 131b and 13212 which also have in them the main inlet and outlet ports. Each piston 129 and 130 is secured by a pin 135 and 136 to a connecting element 137 and 138 respectively. The elements embrace eccentrics 139 and 140 respectively splined at 141 onto the drive shaft 27. Rotation of the drive shaft 27 thus operates the pump to pump fluid drawn from a reservoir (not shown) from the cylinders 131 and 132 through suitable conduits to the inlet port 121 of the valve 109. The strokes of the two pistons are spaced apart by 90 and although this gives an unequal flow of fluid this is not found to be important. It will be appreciated that the pump described can be replaced by any other pump which can be driven off drive shaft 27 and deliver hydraulic fluid at low pressure to the inlet port 121 of valve 109. The fluid from the pump is divided between the valve 109 and between a conduit 128a opening into a cylinder 129a in which is located a plug 130a having a helical path cut round the outer surface thereof. Fluid from the cylinder 129a can pass along the helical path 130a to an outlet 1310 which is connected to drain. A peg 132a extends into the cylinder and engages the helical groove on the plug 130a and the plug is extended out of the cylinder 129a and is formed with a knurled ring 133a by which the plug may be rotated. Rotation of the plug causes the plug to move axially along the cylinder by virtue of the engagement of the peg with the helical groove. A sealing ring 134a is provided to prevent leakage of hydraulic fluid from the cylinder past the plug.

The plug 130a constitutes an hydraulic resistance through which part of the fluid from the pump passes and it is found that by splitting the flow between this resistance and the valve the volume of fluid entering the valve is directly proportional to the speed of the pump and is independent of temperature or viscosity variations in the fluid. Movement of the plug varies the hydraulic resistance offered by this and thus acts to vary the relative volumes of fluid passing through the plug and into the valve.

The outlet ports 122 and 123 from the valve 109 are connected by suitable conduits to opposite sides of a piston 135a working in a cylinder 136a. The cylinder 1360 is formed in the block 115 and is closed by a closure member 137a secured to the block by bolts 138a. Sealing rings 139a and 140a are provided between the closure member 137a and the cylinder 136a and between the closure member 137a and a piston rod 141a respectively. Movement of the valve spool 111 axially from the neutral position shown in FIG. 2B connects the inlet port to the appropriate outlet port so that fluid passes into the cylinder 136a on one side of the piston 135a. Fluid from the other side of the piston 135a is exhausted from the cylinder 136a through the other outlet port and the drain port 124 or 125 at the appropriate end of the valve. Movements of the valve spool 1 1 1 in response to movements of the magnifying lever 67 thus direct fluid to the cylinder 136a to move the piston 135a. The speed and direction of movement of piston 135a is thus at all times directly related to the position of roller 5. Thus any slight or other movement of the sliver sensing roller from its setting causes the main spool valve 111 to control the rate of flow of pressurised fluid to a selected side of the piston 135a depending upon the distance the valve 111 has moved from its neutral position. This valve movement will vary the output shaft speed.

Movement of the piston 135a is used to control the position of a belt in a variable cone belt drive shown in FIGS. 6 and 7. The end of the piston rod 141a has secured thereto a supporting member 142 carrying a frame work 143. The framework 143 lies between an upper driving cone 144 and a lower driven cone 145, the two cones being tapered in opposite directions. A belt 146 engages the two cones to transmit rotation therebetween and the framework 143 lies between the two runs of the belt. The upper end of the framework carries two horizontal arms 147 and 148 lying below and adjacent to the upper cone 144 and projecting towards the run 149 of the belt 146. Each arm 147 and 148 rotatably carries at its end a roll 150 and 151 respectively having a horizontal axis transverse to the axis of cone 144, and the two rolls 150 and 151 engage opposite side edges of the run 149 of the belt, i.e., the belt passes between the two rolls.

The lower end of framework 143 also carries two horizontal arms, one of which is shown at 152 lying above and adjacent to the lower cone 145 and projecting towards the run 153 of belt 146. Again each arm rotatable carries at its end a roll such as 154 having a horizontal axis transverse to the axis of cone 145 and the two rolls such as 154 engage opposite edges of the run 153 of the belt, i.e., the belt passes between the two rolls.

Pivoted at 155 to the upper end of the framework 153 is one end of an am 156 projecting downwardly and towards the run 153 of the belt and having a first tensioning roll 157 rotatably mounted about an axis 158. The tensioning roll 157 engages the outer face of the run 153 of the belt.

Pivoted at 159 to the lower end of the framework 143 is one end of a second arm 160 projecting upwardly LII and towards the run 149 of the belt, and having a second tensioning roll 161 rotatably mounted at its free end about an axis 162. The tensioning roll 161 engages the outer face of the run 149 of the belt. Two tension springs 163 and 164 span the two runs of the belt, and opposite ends of the springs are anchored to the arms and 156 by way of pins 165 and 166 respectively. The springs 163 and 164 bias the tensioning rolls 157 and 161 towards each other to push the two runs of the belt towards each other and so tension the belt. As the springs 163 and 164 act simultaneously on both tensioning rolls 157 and 161 the tensioning forces are equalised on the two runs of the belt and any deflecting forces on the framework 143 are minimised.

It will readily be seen that movement of the piston rod will cause the belt 146 to move axially along the cones 144 and 145 and thus will change the transmission ratio between the two cones.

The cone 144 is mounted on the driving shaft 27 as follows. The shaft 27 is split into two coaxial sections parts 27 extending into lower housing 30a and a part 167 connected to the drive mechanism of the carding machine. The cone 144 is hollow and one end thereof is connected by splines 168 to shaft portion 167, the other end being connected by splines 169 to the shaft portion 27. Grub screw 170 and 171 are provided for locking the cone axially in position on the two shaft sections. The grub screws 170 and 171 may be released to allow the cone to be moved axially to the left along shaft section 167 as seen in FIG. 6 to allow the right hand end of the cone to move past and expose the gap 172 between the ends of the shaft sections 167 and 27. The belt 146 can then be slipped off the right hand end of the cone 144 and withdrawn through the gap 172 to allow replacement of the belt. The old belt may simply be withdrawn from the left hand end of the lower cone 145 which is free. A new belt can then be fitted by fitting on to cone 145 and then being passed through gap 172 and placed over the end of cone 144. The cone 144 is then returned axially to its original position covering the gap 172 and the grub screws 170 and 171 are tightened to lock the cone in its desired axial position.

The lower cone 145 is secured to an output shaft 173 by splines (not shown) and locating grub screws 174 and 175. The shaft 173 is supported to run in bearings 176 and 177 carried by the lower housing 30, a labyrinth seal being provided in association with bearing 176 and a cover plate 179 being secured by bolt 180 to the lower housing 300 at the end 177 of the shaft. The seal 178 and cover plate 179 prevent the escape of oil from the lower housing 30a. The shaft 173 is formed with a worm section 181 with which a pinion 182 meshes. The pinion 182 is carried by a shaft 183 suitably journalled in the housing 30, and the shaft 183 is connected by means (not shown) to the lap feed of the carding machine.

Thus, whenever the belt 146 is axially shifted to vary the transmission ratio between the cones 144 and 145 the speed of the shaft 173 is adjusted and this speed is transmitted by worm and pinion 181 and 182 to the shaft 183 to drive the lap feed roller at a variable speed.

Operation of the complete system will now be apparent. The position of the lever system is set by coarse adjustment member 55 and fine adjustment member 101 so that when a sliver of the desired thickness lies between the rollers 5 and 6 the belt comes to rest approximately at the centre of the cones whilst the spool 111 is hovering about its neutral position shown in FIG. 2. Drive transmission between the cones is thus at a 1/1 ratio so that shaft 173 is driven at the same input speed as shaft 27. The shaft 183 is thus driven at a speed proportional to that of input shaft 27, and this acts to control the lap feed, feeding cotton into the carding machine. After carding the cotton is condensed in a trumpet and passed in sliver form between the rollers 5 and 6 over the knock off motion 26 and then to a coiler shown schematically at 184 which coils the sliver into a receiving can. The coiler 184 is driven from shaft 27 by gears 185 and 186.

So long as the sliver retains the desired thickness the lever and hydraulic system remain stationary and the machine runs as described. If a variation in sliver thickness occurs the roller 5 is either raised or lowered with respect to roller 6 so that the bell-crank lever 45 pivots about shaft 52. This pivotal movement is magnified by lever 67 and the lower end 107 of this lever causes the spool 111 to move axially in the housing 110 so that fluid flows from inlet port 121 through one of the outlet ports 122 or 123 to the appropriate side of the piston 135. The piston 135 thus moves and the piston rod shifts the belt 146 axially so varying the transmission ratio between the cone 144 and 145. The speed of rotation of shaft 173 is thus changed, so changing the speed of shaft 183 and changing the speed of the lap feed. The rate of feed of cotton into the carding machine is thus changed, the change being in such a sense as to vary the thickness of the sliver leaving the carding machine, so that this regains the desired thickness.

The low friction in the lever system and in the valve system make the apparatus very sensitive to even very small changes in sliver thickness, and the arrangement ensures that a correcting factor is continuously applied to the lap feed whenever the sliver deviates from the required thickness. This continuous correction movement ceases immediately the sliver possesses the desired thickness and does not restart until the sliver again deviates from standard.

What I claim is:

1. Apparatus for controlling the count of slivers fed from a carding machine having a driven feed means by varying the rate of said driven feed means, said apparatus comprising roller-sensing means having sliver engaging surfaces receiving said sliver from said carding machine, at least one of said sliver engaging surfaces being movable relative to the other in accordance with variations in sliver thickness from a predetermined thickness; a hydraulically-controlled variator for controlling said feed rate; a pump for pumping hydraulic fluid to said variator; a common drive means for driving said rollersensing means and said pump; valve means for controlling flow of hydraulic fluid from said pump to said variator; a hydraulic resistance connected in parallel with said valve to receive a flow of fluid direct from said pump and deliver a flow of fluid direct to drain; and connecting means operably connecting said at least one of said surfaces to said valve means to control said valve means in response to variations in thickness of said sliver in such a way that said variator controls said driven feed means to cause the sliver to tend to resume said predetermined thickness.

2. Apparatus as claimed in claim 1 wherein said roller-sensing means comprises first and second rollers engaging opposite sides of said slivers and said sliver engaging surfaces are the surfaces of said rollers.

3. Apparatus as claimed in claim 1 wherein means are provided for adjusting said hydraulic resistance.

4. Apparatus as claimed in claim 1 wherein said connecting means comprises lever means operable by movement of said at least one of said surfaces to provide a magnified movement to control said valve means. 

1. Apparatus for controlling the count of slivers fed from a carding machine having a driven feed means by varying the rate of said driven feed means, said apparatus comprising roller-sensing means having sliver engaging surfaces receiving said sliver from said carding machine, at least one of said sliver engaging surfaces being movable relative to the other in accordance with variations in sliver thickness from a predetermined thickness; a hydraulically-controlled variator for controlling said feed rate; a pump for pumping hydraulic fluid to said Variator; a common drive means for driving said rollersensing means and said pump; valve means for controlling flow of hydraulic fluid from said pump to said variator; a hydraulic resistance connected in parallel with said valve to receive a flow of fluid direct from said pump and deliver a flow of fluid direct to drain; and connecting means operably connecting said at least one of said surfaces to said valve means to control said valve means in response to variations in thickness of said sliver in such a way that said variator controls said driven feed means to cause the sliver to tend to resume said predetermined thickness.
 2. Apparatus as claimed in claim 1 wherein said roller-sensing means comprises first and second rollers engaging opposite sides of said slivers and said sliver engaging surfaces are the surfaces of said rollers.
 3. Apparatus as claimed in claim 1 wherein means are provided for adjusting said hydraulic resistance.
 4. Apparatus as claimed in claim 1 wherein said connecting means comprises lever means operable by movement of said at least one of said surfaces to provide a magnified movement to control said valve means. 